Flag pattern is a continuation pattern. We have two flag pattern types:
1) Bullish Flag (on the chart) 2) Bearish Flag (Upside down version of bullish flag)
Flag pattern usually consits of 6 waves and CAN‘T cross 50% of the flagpole ! (0.5 fibonacci level)
If this happens,then it is invalidated and no more taken as Flag pattern. In this case,when it crosses 50% (usually 0.618 fibonacci level), we can talk about AB=CD pattern.